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| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2020-05-13 15:32:08 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2020-05-13 15:43:29 +0200 |
| commit | d9d200bcebc1f6e56f0178cbb8db9953e8cc9a11 (patch) | |
| tree | c1baa1417ffe4dfbeef0f7f19803b3e3535e735b /samples/bpf/trace_event_user.c | |
| parent | 24085f70a6e1b0cb647ec92623284641d8270637 (diff) | |
dma-mapping: add generic helpers for mapping sgtable objects
struct sg_table is a common structure used for describing a memory
buffer. It consists of a scatterlist with memory pages and DMA addresses
(sgl entry), as well as the number of scatterlist entries: CPU pages
(orig_nents entry) and DMA mapped pages (nents entry).
It turned out that it was a common mistake to misuse nents and orig_nents
entries, calling DMA-mapping functions with a wrong number of entries or
ignoring the number of mapped entries returned by the dma_map_sg
function.
To avoid such issues, let's introduce a common wrappers operating
directly on the struct sg_table objects, which take care of the proper
use of the nents and orig_nents entries.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'samples/bpf/trace_event_user.c')
0 files changed, 0 insertions, 0 deletions